Lockup one-way torsional force exerting device



March 23, 1948. Q HE'BNKER 2,438,381

LOCK-UP ONE-WAY TORSIONAL FORCE EXERTING DEVICE Filed Feb. 25, 194e 2 sheets-snaai 1 March 23, 1948. o. H. BANKER 2,438,381

LOCK-UP ONE-WAY ToRsIoNAL FORCE EXERT'ING DEVICE Filed Feb. 25, 1946 2 sheets-Sheet 2 gli fi 55 68a 69a 342'/ Patented Mar. 23., 1948 LOCKUP GNEWAY TORSIONAL FRCE EXERTING DEVIGE Oscar H. Banker, Evanston,.lll., assigner to New Products Corporation, Chicago, Ill., a ycorporation of'Delaware- Application February 25, 194:6, Serial Nm 649,930

This invention concerns change-speed. gearing power trains or the like having a one-way torsional force exerting device therein and relates more particularly to an improved means for locking up the device so its associated power train is divested of its overrunning character,

In some forms of automatic change-speed ap'- paratus a lower speed transmitting power train will have associated therewith a device that enables the power train to transmit vdriving force in only one direction whereby such power train is adapted to overrun and thereby remain mobi'- lized (in contrast to .bein-g' established) during establishment and operation' of a higher' speed train between drive and driven members common to the lower speed train. There are times, however, when itl is desired to circumvent this overrunning feature, as in automobile cha-ngespeed transmissions so the engine' can exert braking action through the lower speed power train to the road wheels. Heretofore temporary.I elim*- ination of the overrunning device has been accomplished by employing a bridging ring having a splined connection with the driven part ofthe device together with a jaw clutch for connecting said ring with the driving part. With this conventional lock-up bridging structure it is possible under certain circumstances to so tightly wedge the clutch teeth, pursuant to their being meshed, that it is extremely diiiicult to'disengage the clutch.

The principal object of the invention isl the provision of a lock-up structure for a oneeway torsional force exerting device that is operable without the contingency of so wedging the meshable teeth thereof that it is difcult to subsequently demesh these teeth for terminating. the locked-up condition. In accomplishing this object a bridging structure of the lock-up device is provided with a circumferential lost-motion connection withone element of the torsional torce exerting device, and a jaw clutch having teeth components respectively constrained for rotation with the bridging structure and with the other part of the device so constructed that backlash exists between the clutch teeth when engaged, and means is provided for operation while the clutch is demeshed for effecting limited. rotation of said bridging structure relatively to the one part of the device in one direction whereby a condition permitting of circumferential. relative movement in a limited amount will prevail between the drive and the driven. parts of the device after engagement of the clutch.

Another object of the-invention is the provision of a lock-up mechanism for an overrunning clutch` device and wherein. there is a bridging structure, having elements meshed with. elements on the driven part of. the device and on a coaxial member in a manner that the bridging structure isl slidably adjustableaxially of said partv and said member'while establishing a driving connection therebetween, together witha jaw clutch having toothed. counterparts so. disposed respectively upon the. bridging: structure and. upon. the driving part of the. overrunning clutch that the. clutch teeth.. are: rneshable pursuant to. adjustment of the bridging structure. in one. axial direction, but because of `the. driven member. being driven. from the driven. partei, the overrunning clutch through the bridging structure. during the. transmission of driving force,y said., meshed. elements grip and resist axial adjustment. of the structure and meshing, of. the jaw clutch,v teeth exceptingl when no force is beingY transmitted. This assuresthat the clutch will not. be engaged. excepting when the rotative position of the bridging structurev relatively to the driven part. of the overrunni'ng clutch device is-f such that the engagement of the clutch cannot. incur the wedged condition of its teeth.

Anotherv object of. the invention is the provision of a lock up mechanism for the above de'- scribedy purpose which employs spring members between the meshed elements ofthe bridging structure and the driven part of. the overrunning. clutch to urge the bridging structure rotatively relatively to the driven part, as facilitated by backlash between the meshed elements; for conditioning the' bridging structure so jaw' clutch counterparts respectively upon saidV structure and upon the. driving part. of' the clutch willnot wedge into a. tight non-extractable condition pursuant to. their being4 meshed.

These` andi other desirable objects4 i'nlfierentl in and encompassed by the invention will be more clearly understood after reading the ensuing description with reference to the annexed drawings, wherein:

Fig, l is a partially diagrammatic View of power transmitting gear trains. in one form `of changespeed transmission and showing partly in: elevation and partly in. section a torsional force exerting device inthe form of an overrunning clutch together with a lock-up mechanism therefor embodying a preferred. form of the invention.

Eig. 2 is. a fragmentary sectional view of the overrunning, clutch and lock-up mechanism of Fig. 1 but. illustrated with the. lock-up mechanism inits inoperative position.

Fig. 3 is a fragmentary sectional view taken on the line 3-3 of Fig. 2.

Fig. 4 is a fragmentary sectional view taken on the line 4-4 of Fig. 1.

Fig. 5 /is a fragmentary sectional view taken on the line 5-5 of Fig. 2.

Fig. 6 is an elevational View partly in section of the overrunning clutch device illustrated rin Fig. 1 but having associated therewith a modied form of lock-up mechanism constituting a second embodiment of the invention.

Fig. 7 is a fragmentary sectional View taken on the line 1 of Fig. 6.

Fig. 8 is a fragmentary sectional view taken on the line 8-8 of Fig. '1.

Figure 9 is a View taken similarly to Fig. 8 illustrating a third embodiment of the invention.

With continued reference to the drawings, at-

tention is particularly directed to Fig..1 because of its showing an environment wherein a mechanism embodying the present invention has utility. Part of a change-speed transmission is i1- lustrated in Fig. 1. This transmission has a drive shaft diagrammatically represented by a straight line. ASaid drive shaft is arranged con- 1ventionally coaxially with a driven shaft I2 also diagrammatically represented by a single heavy Iline. Drive shaft II has a gear I3 constrained for rotation therewith. Teeth I4 of thegear I3 mesh with the teeth of a gear I5 which is rotatable about a countershaft supporting rod I3 having one end supported in a-gear box wall I1. Countershaft gear l5 has a splined driving connection at I3 with a tubular countershaft I9. The countershaft is rotatively supported on vthe rod I6 by axially spaced sets 2| of bearings, one of such sets being shown.

A bearing sleeve 22 on the countershaft rotatively supports a driven part 23 of an overrunning clutch unit 24 which is a form of one-way vtorsional force exerting device. The driving part, 25, of the device 24 is formed integrally Vstructure 32.

4| on an axially shiftable ring 42 constitute the V other counterpart. Ring 42 has a splined connection 43 with the shaft I2.

A second jaw clutch 44 is adapted to optionally establish a driving connection between the gears 31 and I4. Avtoothed counterpart 45 of this clutch is meshable with a toothed counterpart 46 thereof which has a splined connection 41 with the hub of gear 31. Still another jaw clutch 48 has a counterpart of clutch teeth 49 on the inner periphery of an axially-projecting annular portion 5| of the overrunning clutch `driving part 25 and a counterpart of teeth 52 on thetbridging The teeth of clutch 43 are optionally meshable and demeshable by axially shifting of the ring 32 between the -positions shown in Figs. 1 and 2.

with the gear I5 and has a perfectly cylindrical Y inner periphery 26 for frictional engagement with clutch rollers 21; Figs. 1, 2 and 5,. vThe clutch rollers are spring-urged into wedging relation between the periphery 26 and the profiles 28 of circumferentially spaced cams 29 on the outer periphery of the driven part 23. The device 24 is of conventional construction, and, any other form of overrunning clutch device may of .course be substituted therefor. 1n the'operation of this device rotation of the driving part 25 relatively to the driven part 23 in the clockwise direction t as viewed in Fig. 5 is precluded by the rollers 21 ternal spline members 34 `of the bridging structure mesh with exterior spline mmebers 35 on Y the driven part 23 and with exterior spline members 36 on the gear 3|. Counter-shaft gear 3| meshes with a gear 31 which is mounted for rotation on the shaft I2. A jaw clutch 38 is for optionally connecting the gear 31 with the shaft I2. Teeth 39 on the hub of the gear 31 constitute one counterpart of the clutch 38 while teeth Assuming'the clutch 44 to be disengaged and the clutch 38 to be engagedfas illustrated in Fig. l, and further assuming the clutch 48 'to be disengaged as illustrated inY Fig. 2, drivingY force canbe transmitted from the drive shaft II to the driven shaft I2 in a counter-clockwise direction, as these shafts are viewed from the right in Fig. 1. Such drive is through a relatively low speed power train'comprising the gears I4 and l5, overrunning clutch device 24, the bridging structure 32, gears 3| Iand 31, and the clutch 33. Should it be desired to Adrive the driven shaft I2 at a faster speed Arelatively to the drive shaft II, this Acan be done by interrupting theV driving force applied to the drive shaft so that it and the gear I4 will Y'de'celerate while the driven shaft I2 and the load driven thereby, due to their inertia, conl' tinue to rotate without substantial abatement of speed as permitted by the overrunning clutch device 24. The teeth 46 of Yclutch 44 are constrained to revolve at the unabated speed of the driven Vshaft I2 whereas the teeth 45 of this clutch are constrained to decelerate with the drive shaft, so that ultimately the teeth 45 decelerate to synchronize withrthe teeth 46 whereupon clutch 44 can be engaged for establishing a'direct driving connectionY between theshafts .II and I2. VDriving force is then transmittable `so that upon subsequent disengagement of the clutch 44 and the speeding up of thedrive shaft the lower speed power train will become effective automatically for transmitting power.

During operation of the lower speed power train, the driven shaft I2 is Vunconstrained from rotating faster than the drive shaft so that when utilized under these conditions( uponV a motor vehicle the apparatus is ineffective for transmitting braking force from the vehicle Yengine'tol the load wheels. However, it is possibile to convert the low speed power train into a two-way drive power L train so the engine canserve as a brake or so the vehicle can be towed to tr'ansrniticranking force from the road wheels Vto the engine. Conversion of the'V overrunning power train into a two-way force transmitting power train is ac- `Acomplished by axially shifting the bridging structure 32 from the Fig, 2 position to thev Fig. 1 position for engaging the clutch 48.

If the gear 3l were connected rigidly with the overrunning clutch driven part 23 as by means of a sleeve upon which the splines 35 and 35 were integrally formed, in certain instances it would be possible to mesh teeth of the clutch 43 in such a fashion that the cie-meshing of these teeth would be extremely dinicult or impossible without dismantling parts of the apparatus. For example, if the teeth 35 and 36 were formed integrally and the bridging structure 32 was shifted to the left for engaging the clutch 43 while power was being transmitted through the overrunning clutch device from the drive shaft to the driven shaft and it also happened that the teeth 52 were in such a circumferential position relatively to the teeth 49, as illustrated in Fig. 5, that faces A of the teeth 52 wedge orslide tightly against faces B of the teeth 45, pursuant to clutch engagement, as the faces A slide hard against the faces B there would be a reactive force through the structure 32 causing faces C of teeth 34 to slide hard against opposed faces of the splines meshed therewith, so the `structure would lodge tightly between the latter-named spline faces and the faces B, making it impossible to dislodge or disengage the clutch. This wedged condition could not be alleviated by rotating the clutch driving part 25 clockwise relatively to the driven part 23 as viewed in Fig. 5, because of the rollers 2 being wedged between the peripheries 25 and 23; Termination of the wedged condition could not be accomplished by rotation of the clutch driving part 25 in the counter-clockwise direction relatively to the driven 2part E3 because such tendency would simply increase the force between the teeth faces A and B and between the faces C of the bridging member splines 3d and the opposed faces of the splines meshed therewith.

In the present arrangement, the possibility of incurring the just-described wedged locking of the bridging structure is avoided because the gear 3l and the driven part of the overrunning clutch are capable of lirrited relative rotation during operation of the lower speed train. This limited relative rotation is possible principally because the internal splines 34 of the bridging structure 32 have spaces therebetween in excess of the breadth of the teeth 35 as illustrated in Figs. 3 and 5. Only a slight backlash exists between the teeth 36 and 34, as illustrated in Fig. 3, this backlash needing to be only sufficient to provide for freedom of axial movement of the bridging structure relatively to the teeth 35. Also as illustrated in Figs. 4 and 5, backlash is provided between the teeth of the lock-up jaw clutch 48.

When it is desired to close the lock-up clutch d8, the clutch rid will be disengaged and normally the transmission of driving force from the drive shaft to the driven shaft through the low-speed overrunning power train will be interrupted. Under these conditions, because of the inertia of the driven shaft and the load connected therewith, the gear 3 and its hub 54 carrying the splines 36 will have a tendency to rotate clockwise as Viewed in Fig, 5 at greater speed than the bridging structure 32 or either part of the overrunning clutch device. Consequently, the gear hub 54 will have a tendency to rotate the bridging structure 32 clockwise and this bridging structure will in turn tend to rotate the overrunning clutch driven part 23 clockwise so that faces D of the bridging member teeth 34 will be pressed lightly against opposed faces CC of the teeth 55 on driven part 23.

This pressure between the teeth faces D and CC will necessarily be a light force because the over:- running clutch rollers 2T are not adaptedtotransmit force from the driven part 23 to the drive part 25 in the clockwise direction as viewed in Fig. 5.

Ii the bridging structure 32 is now slid endwise for meshing the teeth of the clutch 48, it will be impossible to obtain a wedging condition of these clutch teeth that would prevent or resist disengagement of the clutch. For instance, assuming that the clutch teeth 52 and 49 were in the circumferential relation illustrated in Fig. 5 at the time of meshing, subsequent demeshing could be facilitated by slightly speeding up the drive shaft which would cause the clutch driving member 25 to rotate clockwise relatively to the bridging structure 32 and relieve pressure between the tooth faces A and B. Such clockwise rotation of the driving part 25 relatively to the bridging structure 32 would be possible because of the backlash condition illustrated in Figs. 3 and 5, between the teeth or splines 55 and 34. That is, at the time the clutch 43 was engaged the faces CC and D of the splines 35 and 34 were engaged and faces H and G separated to permit the overrunning clutch driven part 23 to rotate clockwise as viewed in Fig. 5 relatively to the bridging strucu ture 32. Therefore, the entire overrunning clutch unit would be free for clockwise rotation relatively to the bridging structure 32 to relieve pressure between teeth faces A-B and C-D.

Had the circumferential relationship of the overrunning clutch driving part 25 and the bridging structure 32 been such at the time the clutch 43 was engaged that the faces E and F of the teeth 49 and 52 were juxtaposed instead of the faces A and B, subsequent disengagement of the clutch could be facilitated by allowing the road wheels to slightly overrun the engine and thereby cause the gear hub 54 to rotate the bridging structure 32 clockwise relatively to the overruning driving part 25 for separating the teeth faces E and F while the driven part 23 of the overrunning clutch rotates clockwise relatively to the driving part as permitted by the clutch rollers El. Should the clutchl teeth 52 and 43 be in an intermediate position in a circumferential sense at the time of meshing thereof, that is, if these teeth should be between the extreme positions, in one of which the faces A and B slide upon one another and in the other of which the faces E and F slide upon one another, then subsequent demeshing of the clutch' could be facilitated by either accelerating the engine to rotate the overrunning clutch driving part clockwise relatively to the bridging structure 32 or by permitting the road wheels of the vehicle to slightly overrun the engine so that the gear hub 54 would rotate the bridging structure slightly clockwise, as viewed in Fig. 5, as permitted by the overrunning clutch rollers.

If the operator of the apparatus sh-ould attempt to shift the bridging structure 32 for engaging the clutch 48 while power is being transmitted through the low speed power train, his action would be resisted by the gripping of the bridging member splines 34 between the splines 35 and 36. When power is being transmitted through the low speed power train, faces G and H of the splines 34 and 35 will be pressed together `as well as faces D and DD of the splines 34 and 35. If sufficient load is being transmitted through the power train to incur a severe wedging relation between the faces A--B of. the clutch teeth 52 and 49 and the faces G-H ofthe splines 34 and 35, should 4the clutches be engaged While the faces Anand B arel in axial registry, the resistance to axial movement of the bridging structure by the pinching of the splines 3l!l between the' splines 35 and 36 will be suiiicient to preclude engagement of the clutch. i Y

Considering the forward direction of the parts of this rst embodiment, as illustrated in Fig. 5, to be in the clockwise direction, it can be ascertained that incident to shifting the bridging structure 32 for engaging the clutch 48, said bridgingstructure will be rotated to a clockwise limit with respect to the driven part 23. This is because `of the tendency for the gear hub 54 to be rotating at a faster speed inthe clockwise direction relatively tothe driven part 23 while the overrunning clutch unit permits said hub 54 and said driven part 23 to rotate faster in the clockwise direction than the driving part 25. Consequently, the gear hub 54 can be regarded as means operable, while the clutch 48 is demeshed, for effecting limited rotation of the bridging structure 32 relatively to the driven part of the overrunning clutch in a forward direction,

In the second embodiment illustrated in Figs. 6 to 8 one or more leaf spring elements 6i is utilized in lieu of the gear hub 54 for effecting said limited rotation of the bridging structure in a clockwise direction relatively to a driven part 23' of an associated overrunning clutch unit 24'.` which corresponds to the unit 2li in the first embodiment. While only one of the spring elements B! is shown in the drawings, any desired number of them may be employed.

Those parts of the apparatus illustrated in Figs. o to 8 which areY identical with or correspond to respective parts illustrated `in Figs. 1 to are designated by the same respective characters with the addition of a prime. The principal difference in the two embodiments is that the second embodiment employs the aforesaid springs 6l and the hub of the overrunning clutch driven parts 23' is elongated so that it projects into and carries the gear 3|. The radically projecting spline elements 35 on this hub extension mesh with the radially projecting spline elements 34' of the bridging structure 32 as well as with splines t2 in the gear 3i. Snap rings 53 and Se prevent axial displacement of the gear 3l on the hub of the overrunning clutch driven part.

Those of the ribs 35 having a spring element 6I in association therewith are separated into parts 35a and 35h by a transverse groove 55. An end 68 of each spline or rib part 35h is also cut back so that an end portion 61 of the associated spring 6l can extend transversely of the rib along such end without projecting beyond the corresponding ends of the -other splines or ribs 35. The opposite end portion, 68, of each spring 6l engages the opposite end, 69, of its associated rib portion 35h in a manner illustrated in Fig'. 8. Rib portions 35h also are made thinner in a circumferential sense by cutting back the face bridged by the bowed part of their associated springs 6|, so suflicient clearance will always prevail to avoid crushing or bending the spring beyond its elastic Vlimit when there is a forceful tendency for the splines 35' to rotate the bridgingstructure 32 clockwise, as viewed in Fig. '7, when the jaw clutch 58' isclosed.

Each spring 6| is subjected to internalstress causing it to bend to assume a more pronounced curvature than illustrated in Fig. Y8 whereby the endportions 61 and 68 grip the endsof their associated rib portion 35h. While those portions pressure between vthe spline rib faces C'V and D 8 of each spring element adjacently to its Vend portions bear against the end portions of its associated rib 35h, the bowed center part of each spring is caused to exert a force against the opposed face of the adjacent spline 34' and thereby urge the bridging structure 32 clockwise rela- ,tial positions of the bridging structure and of the overrunning clutch driving part V25' are as illustrated as in Fig. 7 so that the clutch tooth faces Aand B are virtually axially aligned to slide against one another while the clutch is being meshed, the lock-out device cannot assume a condition in which'great resistance is incurred in demeshing the clutch. This is because of the backlash condition then prevailing between the faces E and F of the teeth in the clutch 418'V and also the backlash condition provided by the springs 6| between the rib faces G and H'. Under these circumstances, the maximum pressure between the teeth faces A and B will beY that exerted by the springs 6I and this will not be sufficient for causing difficult disengagement of the clutch. Even this pressure could be further diminished by accelerating the vehicle engine for rotating the overrunning clutch part 25 for separating the tooth faces A and B'. On the other hand, ifat the time of engaging the clutch 48', force was being transmitted through the overrun-V ning clutch device so that the drive part 25 vcould not be subsequently rotated clockwise as viewed in Fig. 7 relatively to the driven part 32', when it was subsequently desired to demes'hzthe clutch, the pressure between the tooth faces A' and B' would be limited to the combined forces of the springs 6l as explained above..`

Should the Voverrunning clutch driving part 25? and the bridging structure 32 be in Vsuch asposition of relative rotation at the time of clutch engagement that the tooth faces E 'and F were engaged, the spline rib faces C and'D being enfgaged because of the force of the springs 6i, diminution of the pressure vbetween vthe tooth faces E and F' could be expediently diminished by simply allowing the vehicle engine to decelerate and thereby allow the overrunning clutch driven part 23' and the bridging structure 32' to accelerate relatively to the overrunning clutch driving part 25?, thereby separating the tooth faces E andrF and simultaneously relieve all excepting that imposed thereonV by the springs It can be ascertained from the above descrip-` Y tion of this second embodiment of the invention therefor that the clutch 48 can be demeshed easily irrespective of whether the bridging structure 32 occupies a circumferential position relatively to the overrunning clutch driving part 25' Vfortenlgaging either'th-e clutch tooth faces AV and B' or E.' and F. With neither sets of faces A and B or E and F pressed together there could,rof

course, be no diiculty inV demeshingthe clutch.

where one of the ribs 34", which correspond to v`the ribs 34 in Figs. 6-8 and to the ribs .34 in Figs. 1-5, lhas its ends 66a and 69a cut `back `to receive the ends 61a and `ict .of a spring having a bowed portion Bla reacting against the opposed face of an adjacent tooth 35". In Fig. 9 lthose reference characters followed ,by a double prime or an alphabet letter respectively correspond to the parts in Fig. 8 designated by a reference character with a single prime or without .a suix. This construction is simpler since the groove 65 of Fig. 8 is eliminated. In Fig. 9 the rib face spanned by the bowed portion of the spring is cut back so corresponding faces on other ribs in the same series will abut against `the respectively opposed faces on the ribs ci the meshing serie-s to transmit torsional force from the driven part of the overrunning clutch through the bridging structure and jaw clutch to the driving part of the jaw clutch in the clockwise direction as viewed in Fig. 7, whilesufcient space is preserved between the outback face and the rib face opposed thereto toavoid crushing cr excessive distortion of the spring.

Having described a limited Vnumber of embodiments of the invention with the view of concisely and clearly illustrating the same, I claim:

1. In an overrunning power transmitting train, an overrunning clutch device including a rotatable driving part and a yrotatable driven part coaxial with the driving part, a rotatable driven member coaxial with said driven part, and means for driving said driven member optionally from said vparts comprising a bridging structure having meshed-element connections with said driven part and said driven member and adjustable axially of said parts and said elements incident to sliding the elements in said connections, and a dental clutch including components respectively constrained for rotation with the driving part and with said bridging structure and optionally meshable by the axial adjustment of said structure, and the connection between said structure and said driven part being constructed and arranged to provide for limited relative rotation of said structure and said driven part.

2. In an overrunning power transmitting train, a one-way torsional force transmitting device including coaxial relatively rotatable parts, a member rotatable coaxially of said parts, a bridging structure having splined connections with said member and with one of said parts and being adjustable axially thereof while said connections obtain, and a dental clutch including components respectively on said bridging structure and the other of said parts and optionally meshable by the axial adjustment of said structure, said clutch providing for substantial limited relative rotation between said structure and said other part while meshed, and the connection between said structure and the one part providing for substantial limited relative rotation therebetween.

3. In an overrunning power transmitting train, an overrunning clutch device including a rotatable driving part and a rotatable driven part coaxial with the driving part, a rotatable driven member coaxial with said driven part and having an end portion in adjacent end-to-end relation with an end portion of said driven part, said end portions being externally splined with the same number of spline ribs but with such ribs of the driven part portion having less circumferential breadth than those of said driven member portion, a bridging structure having internal splines of uniform circumferential breadth mutually meshed with the splines of said end por- `.tions and adjustable axially thereof while remainng so mutually meshed, said splines serving to transmitdriving force between the driven parts and the driven member while the external splines grip the internal splines and thereby resist said axial adjustment of said bridging structure, and ,a jaw clutch including toothed counterparts on said structureand said driving and adapted for optional engagement by selective axial adjustment of said structure, and the teeth of said clutch providing for substantial limited relative .rotation of said driving part and structure while the toothed counterparts are meshed.

4. In an overrunning power transmitting train, an overruningclutch device including a rotatable driving part and a rotatable driven part coaxial with the driving part, a rotatable driven member coaxial with said driven part, and having an .end portion in adjacent end-to-end relation with an rend portion of said driven part, said end portions being -externally splined with the same number of spline ribs but with such ribs of the driven part portion having less circumferential breadth than those of said driven member portion, a bridging structure having internal splines of uniform circumferential breadth mutually meshed with the splines of said end portions vand adjustable axially thereof while remaining so mutually meshed, said splines serving to transmit driving force between the driven part and the driven member whilethe external splines grip the internal splines and lthereby resist said axial adjustment of said bridging structure and means operable to establish a driving connection between said structure yand said driving part incident to adjustment of said structure in vone axial direction and to terminate such connection incident to adjustment `of said structure in the opposite direction, and said driving connection establishing means being of a character to facilitate substantial limited relative rotation of said driving part and said structure driving the establishment of such connection.

5. In a lock-up mechanism for an overrunning clutch device which has coaxial relatively rotatable driving and driven parts and means to limit forward rotation of the driving part relatively to the driven part while facilitating retrograde rotation of the driving part relatively to the driven part, the combination of a bridging structure, meshed elements respectively constrained for rotation with said driven part and with said structure, said meshed elements being constructed and arranged to provide for axial adjustment of said structure relatively to said parts and for limited rotation of said structure relatively to the driven part, a dental clutch comprising components respectively constrained for rotation with said structure and said driving part and optionally meshable pursuant to axial adjustment of said structure, and means operable while said clutch is demeshed for effecting the limited rotation of said structure relatively to said driven part in a forward direction.

6. In the lock-up mechanism for an overrunning clutch device which has coaxial relatively rotatable driving and driven parts and means to limit forward rotation of the driving part relatively to the driven part while facilitating forward rotation of the driven part relatively to the drive part, the combination of a bridging structure. meshed elements respectively constrained for rotation with said driven part and with said structure, said meshed elements being constructed and arranged toprovide for axial adjustment of said aissgaa'i 'structure relatively to saidpartsl and for limited establishment of such connection.

Y 7. In a lock-up mechanism for an overrunning clutch device which has coaxial relatively rotatable driving and driven parts and means to limit forward rotation of the driving part relatively to the driven part while facilitating forward rotation'of the driven part relatively to the drive part, said 'driven part having a splined portion, a bridging structure having a splined portion of which the spline ribs are meshed with those of the driven part splined portion, the spaces between the ribs of at least one of said splined portions having greater breadth than such ribs to facilitate limited relative rotation'of said structure and driven part, spring means between certain of the meshed spline ribs and reacting 'therebetween to urge said structure rotatively for- 12 substantial limited relative rotation of said driviing part and said structure during the establishment of such connection.

8. The combination set forth in claim v'7,ovrvhrerein said lspring means comprises an elongated bowed spring member extending lengthwise of and between opposed faces of adjacent ribs'hav` ing end sections projecting transversely of one of said adjacent ribs at its ends. Y Y

9. In a lock-up mechanism for an overrunning clutch device having coaxial driving and driven parts .of which the latterisrotatable forwardly relatively to the former and ofxwhich partsthe driven part has a series of spline ribs extending axially thereof, abridging structure having a A series of spline ribs meshed with those of the driven part, the ribs in' one ofr said series being of less width linearly of the pitch'linefof such series than the corresponding width of thespaces lbetween the ribs of the other series Ato facilitate limited relative rotation of said structure and said driven. part, spring means between' a face on certain of the ribs in oneseries' and theV opposed faceion adjacent ribs of the other series for vurging the structure to rotate forwardly relatively to the ldriven part, a jaw clutch"meansadapted to'connect said'structure with said driving'pa'rt in a manner adapting limited relative rotation be` tween the structure and said` driving part, and

Iet

at least one of the opposed rib faces'being vcut back to remain spaced apart and'avoid excessive gripping of the spring therebetween while corresponding faces of other teeth'in the two series abut together for transmitting torsional force forwardly from the driven part through Vsaid structure and said clutch to the driving part;

OSCAR H. BANKER. 

